Male Reproductive System

• Organs of Male Reproduction

– Gonads (Testes)

• produce gametes (sperm)

• secrete the sex steroid hormones

– Ducts (reproductive tract)

• Store Sperm

• Transport sperm

– Accessory Organs

• Secrete substances that support sperm

– External genitalia

• Penis

• scrotum

• Testes

– Located in the scrotum

• cremaster and dartos muscles help to regulate temperature

– Within the testes:

• seminiferous tubules

–developing sperm

–sustentacular cells

• interstitial cells

§ Spermatogenesis

• The testes descend from the abdomen during fetal development

• Ducts

–Epididymis

– Vas deferens

– Ejaculatory duct

– Urethra

•Accessory Glands

– Seminal vesicles

– Prostate gland

– Bulbourethral glands

• Semen

– sperm plus seminal fluid

– 50-150 million sperm/ml

– includes prostaglandins, bicarbonate, fructose, antibiotics, & enzymes that activate sperm

• Penis

– root & body

– glans & prepuce

– erectile bodies

• corpus spongiosum

• coropora cavernosa

– erections under the control of parasympathetic stimulation

– ejaculation: sympathetic

• Hormone Control of Male Reproduction

• Other Functions of Testosterone

– development, growth, & maintenance of male sex organs

– bone and muscle growth

– 2^o sex characteristics

– aggression?

– libido

Female Reproductive System

• Organs of Female Reproduction

– Gonads (Ovaries)

• produce gametes (ova)

• secrete the sex steroid hormones

– Reproductive tract

• uterine tubes

• uterus

• vagina

– External Genitalia

• Ovaries

– Held in place by ligaments

• ovarian ligaments

• suspensory ligaments

– Contain thousands of follicles

– Each follicle contains one ovum

– Each month one follicle matures

– At ovulation: a mature follicle releases an ovum

– hormones secreted include

• estrogens

• progesterone (progestins)

• Uterine Tubes

– Smooth muscle tubes

– Lined with ciliated columnar epithelium

– Other features:

• infundibulum

• frimbriae

• ampulla

– Site of fertilization

– Pathway to uterus

• Uterus

– “Womb”

– Held in place by ligaments

• broad ligament

• round ligament

– Site of

• embryo implantation

• embryo and fetal development

• labor

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– Anatomical regions of Uterus

• fundus

• body

• cervix

– Uterine wall consists of three layers

• endometrium

• myometrium

• perimetrium

– Endometrium divided into

• functional zone

• basilar zone

• Vagina

– muscular tube between urinary bladder and rectum

– pathway for sperm

– pathway for menstrual flow

– birth canal

– vaginal opening may be partially covered by the hymen

– lined with stratified squamous epithelium

• External genitalia: vulva

– labia minora

– clitoris

– vestibule

– labia majora

– mons pubis

• Exocrine glands of the vulva

–Paraurethral glands

–Greater and lesser vestibular glands

• Mammary Glands

– several lobes

– each lobe consisting of numerous lobules

– lactiferous ducts drain each lobe

– near nipple, the ducts expand into sinuses

– the breast is supported by numerous suspensory ligaments

Ovarian cycle

• 1^st two weeks: pre-ovulatory phase:

– Follicle maturation

• On day 14 of a 28 day cycle:

– ovulation

• Last two weeks: corpus luteum development

Uterine cycle

• 1^st 3-7 days: menses

– loss of functional zone layer of endometrium

• 2^nd week: proliferative phase

– restoration of endometrial functional zone layer

• 3^rd and 4^th weeks: secretory phase

– active endometrial glands

• Hormonal Control of Female Reproduction

• If (after two weeks) no pregnancy:

– corpus luteum shuts down.

– E & P secretion stops

– endomentrium loses hormonal support

– menses begins

• If a successful fertilization occurs:

– corpus luteum does not shut down.

– E & P secretion continues

– endomentrium is maintained

– pregnancy continues

• Why doesn’t the corpus luteum shut down if an early embryo is present?

• General Function of Progestins

– preparation of the body for pregnancy